Question

$27 \div 9 + 6 \times 4 - 6 =$

• A. 22
• B. 23
• C. 21
• D. 24

Answer 1

Answer:

C. 21

Mathematical Order of Operations (BODMAS/PEMDAS)

To solve this expression, follow the standard order of operations, which ensures consistent results in mathematical calculations:

• Brackets / Parentheses
• Orders / Exponents
• Division and Multiplication (from left to right)
• Addition and Subtraction (from left to right)

Step-by-Step Calculation:

1. Division: Perform the division first according to the hierarchy. 27 ÷ 9 = 3. The expression now becomes 3 + 6 × 4 - 6.
2. Multiplication: Perform multiplication next. 6 × 4 = 24. The expression now becomes 3 + 24 - 6.
3. Addition: Perform addition from left to right. 3 + 24 = 27. The expression now becomes 27 - 6.
4. Subtraction: Perform the final subtraction. 27 - 6 = 21.

Key Tips for Competitive Exams:

• Avoid Common Errors: Many candidates incorrectly perform operations in the order they appear from left to right (e.g., 27 ÷ 9 = 3, 3 + 6 = 9, 9 × 4 = 36, 36 - 6 = 30). This is incorrect because multiplication and division must always precede addition and subtraction.
• Practice: Mastering the BODMAS rule is essential for simplifying complex arithmetic expressions, which frequently appear in the quantitative aptitude section of Kerala PSC exams.